Certain commercial polymers, such as bisphenol A polycarbonates, are believed to have glass transition temperatures and notched Izod impact strength desirable for thermoformed film and sheet but are believed to require drying prior to thermoforming. Other commercial polymers, such as acrylics and certain impact modified acrylics, are believed to have the glass transition temperatures desired for thermoformed film and sheet and are not believed to require drying prior to thermoforming; however, they are believed to have room temperature notched Izod impact strengths of typically less than 2 ft-lb/in which is often not desirable for certain end use applications. Thus, there is a commercial need for a polymeric material with a combination of properties making it ideal for thermoformed film and sheet applications including a combination of two or more of high notched Izod impact strength, certain inherent viscosities, certain glass transition temperature (Tg), certain flexural modulus, good clarity, and good color.
In addition, there is a commercial need for a polymeric material with a combination of properties making it desirable for thermoformed film and sheet applications including a combination of three or more of high notched Izod impact strength, certain glass transition temperature (Tg), certain flexural modulus, good clarity, and good color.
Further, there is a commercial need for a polymeric material with a combination of properties making it desirable for thermoformed film and sheet applications including a combination of all of the following properties: high notched Izod impact strength, certain glass transition temperature (Tg), certain flexural modulus, good clarity, and good color.
In addition, in one embodiment, there is a need in the art for polyesters comprising 2,2,4,4-tetramethyl-1,3-cyclobutanediol, ethylene glycol, and, cyclohexanedimethanol, which have good color and/or good clarity and for process(es) to prepare these polyesters.
Further, in one embodiment, there is a need in the art for a process which makes it easier to produce the polyesters of the inventions without at least one of the following occurring: bubbling, splay formation, color formation, foaming, off-gassing, and erratic melt levels, i.e., pulsating of the polyester or the polyester's production and processing systems. There is also a need in the art for a process which makes it easier to produce the polyesters of the invention in large quantities (for example, pilot run scale and/or commercial production) without at least one of the aforesaid difficulties occurring.